package com.webank.weevent.governance.configuration;

import java.io.IOException;
import java.net.HttpURLConnection;
import java.net.InetAddress;
import java.net.Socket;
import java.security.cert.X509Certificate;

import javax.net.ssl.HostnameVerifier;
import javax.net.ssl.HttpsURLConnection;
import javax.net.ssl.SSLContext;
import javax.net.ssl.SSLSession;
import javax.net.ssl.SSLSocket;
import javax.net.ssl.SSLSocketFactory;
import javax.net.ssl.TrustManager;
import javax.net.ssl.X509TrustManager;

import org.springframework.http.client.SimpleClientHttpRequestFactory;
import lombok.extern.slf4j.Slf4j;

@Slf4j
public class HttpsClientRequestFactory extends SimpleClientHttpRequestFactory {

    @Override
    protected void prepareConnection(HttpURLConnection connection, String httpMethod) {
        try {
            if (!(connection instanceof HttpsURLConnection)) {
                throw new RuntimeException("An instance of HttpsURLConnection is expected");
            }

            HttpsURLConnection httpsConnection = (HttpsURLConnection) connection;

            TrustManager[] trustAllCerts = new TrustManager[]{new X509TrustManager() {
                @Override
                public java.security.cert.X509Certificate[] getAcceptedIssuers() {
                    return null;
                }

                @Override
                public void checkClientTrusted(X509Certificate[] certs, String authType) {
                }

                @Override
                public void checkServerTrusted(X509Certificate[] certs, String authType) {
                }

            }};

            SSLContext sslContext = SSLContext.getInstance("TLS");
            sslContext.init(null, trustAllCerts, new java.security.SecureRandom());
            httpsConnection.setSSLSocketFactory(new MyCustomSSLSocketFactory(sslContext.getSocketFactory()));

            httpsConnection.setHostnameVerifier(new HostnameVerifier() {
                @Override
                public boolean verify(String s, SSLSession sslSession) {
                    return true;
                }
            });

            super.prepareConnection(httpsConnection, httpMethod);
        } catch (Exception e) {
            log.error(e.getMessage());
        }
    }

    /**
     * We need to invoke sslSocket.setEnabledProtocols(new String[] {"SSLv3"});
     */
    private static class MyCustomSSLSocketFactory extends SSLSocketFactory {

        private final SSLSocketFactory delegate;

        public MyCustomSSLSocketFactory(SSLSocketFactory delegate) {
            this.delegate = delegate;
        }

        @Override
        public String[] getDefaultCipherSuites() {
            return delegate.getDefaultCipherSuites();
        }

        @Override
        public String[] getSupportedCipherSuites() {
            return delegate.getSupportedCipherSuites();
        }

        @Override
        public Socket createSocket(final Socket socket, final String host, final int port, final boolean autoClose)
                throws IOException {
            final Socket underlyingSocket = delegate.createSocket(socket, host, port, autoClose);
            return overrideProtocol(underlyingSocket);
        }

        @Override
        public Socket createSocket(final String host, final int port) throws IOException {
            final Socket underlyingSocket = delegate.createSocket(host, port);
            return overrideProtocol(underlyingSocket);
        }

        @Override
        public Socket createSocket(final String host, final int port, final InetAddress localAddress,
                                   final int localPort) throws IOException {
            final Socket underlyingSocket = delegate.createSocket(host, port, localAddress, localPort);
            return overrideProtocol(underlyingSocket);
        }

        @Override
        public Socket createSocket(final InetAddress host, final int port) throws IOException {
            final Socket underlyingSocket = delegate.createSocket(host, port);
            return overrideProtocol(underlyingSocket);
        }

        @Override
        public Socket createSocket(final InetAddress host, final int port, final InetAddress localAddress,
                                   final int localPort) throws IOException {
            final Socket underlyingSocket = delegate.createSocket(host, port, localAddress, localPort);
            return overrideProtocol(underlyingSocket);
        }

        private Socket overrideProtocol(final Socket socket) {
            if (!(socket instanceof SSLSocket)) {
                throw new RuntimeException("An instance of SSLSocket is expected");
            }
            ((SSLSocket) socket).setEnabledProtocols(new String[]{"TLSv1"});
            return socket;
        }
    }
}
